Liquid crystal display apparatuses that can be driven with a comparatively small amount of power have been widely used not only as image display apparatuses to be provided in stationary apparatuses but also as image display apparatuses to be provided in portable phones. Among these liquid crystal display apparatuses, there is a liquid crystal display apparatus in which a gradation to be displayed by a pixel is controlled by (i) supplying, to a data signal line driving circuit, a digital signal indicating a gradation of each pixel and (ii) causing the data signal line driving circuit to apply, to a data signal line, a voltage corresponding to a value of the digital signal.
In a liquid crystal display apparatus, the transmission of light emitted from a backlight is adjusted by adjusting the way a liquid crystal layer polarizes light. This causes deterioration in efficiency in the use of light as compared with a CRT (cathode-ray tube) using direct fluorescence emission. Furthermore, a color filter is used for a color display. This causes further deterioration in efficiency in the use of light by the liquid crystal display.
In order to solve this problem, Patent Document 1 (Japanese Unexamined Patent Publication No. 118521/1990 (Tokukaihei 2-118521; published on May 2, 1990)) discloses a technique of improving transmittance in a white state by providing pixels each including not only R (red), G (green), and B (blue) sub-pixels but also a W (white) sub-pixel that uses no color filter.
For example, the W sub-pixel is set to have a gradation level smaller than those of the R, G, and B sub-pixels, and the R, G, and B sub-pixels are corrected to have gradations corresponding to differences between the luminance of the W sub-pixel and the luminances of the R, G, and B sub-pixels, respectively. This makes it possible to realize an entirely bright display.